Juzuba and Jūka-chōji — The Exquisite Quenching Techniques That Perfected the Chōji Hamon

The World Beyond Choji-ba

Among the hamon of Japanese swords, the "choji-ba," named for its rounded heads arranged in succession like clove buds, is a representative irregular hamon known for its gorgeousness. Particularly, the sword smiths who flourished in Bizen Province (present-day eastern Okayama Prefecture) developed this choji-ba to a high degree.

Within this choji-ba exists an even more refined variation: the "suzuha" and the "juuka-choji." Both are crystallizations of the sword smith's skill, pushing the fundamental choji hamon to its limits through hardening.

Suzuha—The Ordered Beauty of Aligned Heads

The suzuha is a hamon in which the heads of choji are arrayed with regularity in nearly the same size and spacing, appearing like prayer beads strung together.

While ordinary choji-ba is an irregular succession of heads of varying sizes, suzuha is characterized by consistency in the size and spacing of the heads. This "alignment" is in fact extremely difficult to achieve. The hardening clay must be applied repeatedly in a uniform rhythm, and the cooling during hardening must be controlled so that the heads align as intended. It is a sophisticated hamon that overlays orderly regularity upon the gorgeousness of an irregular hamon.

Juuka-choji—Choji Blooming Doubly

The juuka-choji is a hamon in which the heads of choji are layered in two stages, appearing as though flowers bloom in double layers. It creates a scene with three-dimensional depth and splendor, as if a smaller choji sits atop another.

The juuka-choji is considered especially magnificent among the variations of choji-ba, belonging to the lineage of grand and splendid choji seen in the works of the Fukuoka Ichimonji school and others during the height of the Bizen tradition in the Kamakura period. Creating double-layered heads requires complex shapes to be drawn at the hardening-clay stage, and during hardening to work the nie and nioi while maintaining that form without distortion—a control of extreme delicacy.

Tsuchiooki and Nioiguchi Supporting the Hardening

To create precise choji such as suzuha or juuka-choji, the precision of tsuchiooki (hardening-clay placement) determines everything. This is because the outline of the hardening clay applied to the edge becomes directly the form of the hamon after hardening.

The sword smith draws the desired succession or layering of choji with the hardening clay, as if sketching a preliminary draft. Then, managing the heating temperature and cooling speed during hardening, the smith finishes the work so that the "nioiguchi" (the bright and dark band at the hamon boundary) stands beautifully along the clay outline. Choji-ba typically shows brilliance with a tight nioiguchi dominated by nioi, and that bright, keen nioiguchi becomes a condition of fine pieces.

Checkpoints for Appreciation

When appreciating suzuha or juuka-choji in practice, viewing them in the following sequence makes the pattern easier to grasp.

1. Shine light at an oblique angle on the blade, following the succession of the hamon as a whole. Confirm in broad outline whether the heads are uniform in size and spacing, and whether there are doubly layered sections.
2. Look closely at the nioiguchi, observing whether the boundary is bright and keen, or blurred.
3. Pay attention to features such as the "ashi" (lines extending from the troughs toward the edge) and the "yo" (small dots appearing within the hamon). Works in which ashi runs long and vigorously never tire the eye with their lively blade interior.

Point lighting is best. Placing a point light source at an oblique angle to the edge and slowly tilting the blade reveals the contrast of the nioiguchi, and the layering of heads and insertion of ashi come into view.

Distinguishing from Similar Hamon

The hamon most easily confused with choji-ba is the "guno-me." The guno-me consists of semicircular hamon arrayed regularly, differing in outline character from choji, where the head swells roundly and the waist narrows. In practice, many hamon combine both, called "guno-me choji," and the boundary is continuous. Since suzuha represents the pinnacle of uniform-headed choji, it may at first impression resemble guno-me, but the character of choji remains in the swelling of the heads and the entry of ashi. Such fine distinctions are difficult to discern through words alone; comparing many examples and cultivating a sense for outline is ultimately the surest path.

Considerations When Examining Condition

Gorgeous choji-ba is also susceptible to the effects of repeated honing. On blades subjected to years of polishing, the hamon heads approach the edge, and the original pattern may appear diminished. When appreciating or acquiring a piece, avoid judging solely by the gorgeousness of the hamon; simultaneously confirm the brightness of the nioiguchi, the soundness of the jigane, and the balance between hamon and form. Choji hardened on a sound blade is more three-dimensional than it appears in photographs, changing expression with each angle of light.

The Splendor Perfected by Bizen

Both suzuha and juuka-choji are refinements of hardening technique polished by Bizen sword smiths who excelled in choji-ba. They can be said to represent the pinnacle of technique, born from taking the fundamental choji-ba to its extreme in the directions of "harmonizing" or "layering."

When appreciating blades with these hamon patterns, I invite you to pay attention to the arrangement and rhythm of the choji heads and the subtlety of their layering. Within what appears to be a gorgeous disorder, you should be able to discern the sword smith's precise intention to harmonize the heads and layer the flowers, and the hardening technique that brought that vision to life.

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